The following steps should do after create a blog :
1) Create sitemap, submit to Google
2) Submit your URL to Yahoo! Google and Bing search engines
3) If you have several posts, social bookmark all of them (eg. Digg, StumbleUpon..)
4) Create a Facebook fanpage for your blog, and get people/friends to like it, and share your posts URL on facebook fanpage with short descriptions each time
5) Create a Twitter account and do the same thing as with the Facebook account sharing method
6) Create a Google Plus Account and do the same thing
These are the immediate steps you can take.
After which for long term SEO, you should
1) Write guest posts with dofollow backlinks
2) Submit articles to article directories
3) Social bookmark all blog posts
Read more Why need SEO for websites
I hope this suggestion will help you to promote a website or blog.